mb/google/poppy/variants/nami: remove redundant break

Break never comes after return, remove it.

BUG=N/A
BRANCH=firmware-nami-10775.108.B
TEST=N/A

Signed-off-by: Eric Lai <ericr_lai@compal.corp-partner.google.com>
Change-Id: I005918d6a04cd21df496dea0f2cb1ed6108675af
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33299
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/poppy/variants/nami/mainboard.c

@@ -215,7 +215,6 @@ const char *mainboard_vbt_filename(void)
 		return "vbt-bard.bin";
 	default:
 		return "vbt.bin";
-		break;
 	}
 }